When I press REWIND, the systems jumps back to the VERY BEGINNING OF THE SHOW

I am having the same issue.

Hi Pavony1, thanks for taking the time to create that post and for sharing your experience. I can see how that would get old when you're trying to kick back and enjoy a recording or On Demand. I'd like to ask a few clarifying questions to get us going. Are you able to test if this rewind issue is impacting both DVR and On-Demand? Also, have you completed any troubleshooting steps on your end, to avoid any repeats? 

This is happening on our tv as well for about a month. We have tried installing the app again, but it does not resolve the issue. Xfinity has to know about this.